Asset List Screenlet for Android

Requirements

• Android SDK 4.1 (API Level 16) or above
• Liferay Portal 6.2 CE/EE, Liferay CE Portal 7.0/7.1, Liferay DXP
• Liferay Screens Compatibility app (CE or EE/DXP). This app is preinstalled in Liferay CE Portal 7.0/7.1 and Liferay DXP.

Compatibility

• Android SDK 4.1 (API Level 16) or above

Xamarin Requirements

• Visual Studio 7.2
• Mono .NET framework 5.4.1.6

Features

The Asset List Screenlet can be used to show asset lists from a Liferay instance. For example, you can use the Screenlet to show a scrollable list of assets. It also implements fluent pagination with configurable page size. The Asset List Screenlet can show assets belonging to the following classes:

• BlogsEntry
• BookmarksEntry
• BookmarksFolder
• CalendarEvent
• DLFileEntry
• DDLRecord
• DDLRecordSet
• Group
• JournalArticle (Web Content)
• JournalFolder
• Layout
• LayoutRevision
• MBThread
• MBCategory
• MBDiscussion
• MBMailingList
• Organization
• User
• WikiPage
• WikiPageResource
• WikiNode

The Asset List Screenlet also supports i18n in asset values.

JSON Services Used

Screenlets in Liferay Screens call JSON web services in the portal. This Screenlet calls the following services and methods.

Service	Method	Notes
ScreensddlrecordService (Screens compatibility plugin)	getAssetEntries	With entryQuery
ScreensddlrecordService (Screens compatibility plugin)	getAssetEntries	With companyId, groupId, and portletItemName
AssetEntryService	getEntriesCount

Module

• None

Views

• Default
• Material

The Default Views use a standard RecyclerView to show the scrollable list. Other Views may use a different component, such as ViewPager or others, to show the items.

Portal Configuration

Dynamic Data Lists (DDL) and Data Types should be configured properly in the portal. Refer to the Creating Data Definitions
and Creating Data Lists sections of the User Guide for more details.

Also, to allow remote calls without the userId, the Liferay Screens Compatibility app must be installed in your Liferay instance. You can find this app on Liferay Marketplace.

Offline

This Screenlet supports offline mode so it can function without a network connection. For more information on how offline mode works, see the tutorial on its architecture.

Policy	What happens	When to use
REMOTE_ONLY	The Screenlet loads the list from the portal. If a connection issue occurs, the Screenlet uses the listener to notify the developer about the error. If the Screenlet successfully loads the list, it stores the data in the local cache for later use.	Use this policy when you always need to show updated data, and show nothing when there’s no connection.
CACHE_ONLY	The Screenlet loads the list from the local cache. If the list isn’t there, the Screenlet uses the listener to notify the developer about the error.	Use this policy when you always need to show local data, without retrieving remote information under any circumstance.
REMOTE_FIRST	The Screenlet loads the list from the portal. If this succeeds, the Screenlet shows the list to the user and stores it in the local cache for later use. If a connection issue occurs, the Screenlet retrieves the list from the local cache. If the list doesn’t exist there, the Screenlet uses the listener to notify the developer about the error.	Use this policy to show the most recent version of the data when connected, but show an outdated version when there’s no connection.
CACHE_FIRST	The Screenlet loads the list from the local cache. If the list isn’t there, the Screenlet requests it from the portal and notifies the developer about any errors that occur (including connectivity errors).	Use this policy to save bandwidth and loading time in case you have local (but probably outdated) data.

Required Attributes

• classNameId

If you don’t set classNameId, you must set this attribute instead:

• portletItemName

Attributes

Attribute	Data type	Explanation
layoutId	@layout	The layout to use to show the View.
autoLoad	boolean	Whether the list should be loaded when it’s presented on the screen. The default value is true.
groupId	number	The asset’s group (site) ID. If this value is 0, the groupId specified in LiferayServerContext is used. The default value is 0.
cachePolicy	string	The offline mode setting. See the Offline section for details.
portletItemName	string	The name of the configuration template you used in the Asset Publisher. To use this feature, add an Asset Publisher to one of your site’s pages (it may be a hidden page), configure the Asset Publisher’s filter (in Configuration → Setup → Asset Selection), and then use the Asset Publisher’s Configuration Templates option to save this configuration with a name. Use this name in this attribute.
classNameId	number	The asset class name’s ID. Use values from the portal’s classname_ database table.
firstPageSize	number	The number of items to retrieve from the server for display on the list’s first page. The default value is 50.
pageSize	number	The number of items to retrieve from the server for display on the second and subsequent pages. The default value is 25.
labelFields	string	The comma-separated names of the DDL fields to show. Refer to the list’s data definition to find the field names. For more information on this, see Creating Data Definitions. Note that the appearance of these values in your app depends on the layoutId set.
customEntryQuery	HashMap	The set of keys (string) and values (string or number) to be used in the AssetEntryQuery object. These values filter the assets returned by the Liferay instance.

Methods

Method	Return	Explanation
loadPage(pageNumber)	void	Starts the request to load the specified page of assets. The page is shown when the response is received.

Listener

Asset List Screenlet delegates some events to an object or a class that implements the BaseListListener interface. This interface lets you implement the following methods:

• onListPageFailed(int startRow, Exception e): Called when the server call to retrieve a page of items fails. This method’s arguments include the Exception generated when the server call fails.

• onListPageReceived(int startRow, int endRow, List<Model> entries, int rowCount): Called when the server call to retrieve a page of items succeeds. Note that this method may be called more than once; once for each page received. Because startRow and endRow change for each page, a startRow of 0 corresponds to the first item on the first page.

• onListItemSelected(Model entries, View view): Called when an item is selected in the list. This method’s arguments include the selected list item (Model).

• error(Exception e, String userAction): Called when an error occurs in the process. The userAction argument distinguishes the specific action in which the error occurred.